Walkers, comprising light-weight tubular frames which form pairs of opposed legs joined in parallel spaced relation are in widespread use to assist those in need of support to better maintain stability and balance while walking or standing. A user stands between the leg pairs and grips the tubular frame, placing weight on the legs while standing or pushing the walker while walking. Conventional walkers are suited for traversing level ground and have legs of substantially equal length. However, when climbing stairs, a curb or an incline such walkers cannot provide reliable support to the user, who is thus vulnerable to injury from a fall due to loss of balance. There is clearly a need for an improved walker which will allow traversal of stairs, curbs and inclines with greater safety.